This invention relates to installing sleeves in heat exchanger tubes and, more particularly, to the utilization of shaped explosive charges to weld portions of the sleeves to portions of the tube within the tube sheet and to expand portions of the sleeve to portions of the tube beyond the tube sheet.
Heat exchanger tubes fail in service from highly localized defects with the remainder of the tube in essentially perfect condition. Often, it is impractical or untimely to replace defective tubes and the tube is removed from service by plugging, thereby ending its useful life. If a large number of tubes are plugged, the efficiency of the heat exchanger may be reduced to such an extent that the usefulness of the heat exchanger is impaired. Besides repairing defective tubes, sleeves may also be utilized to lower the heat flux through a portion of the tube wall by increasing the effective tube wall thickness and to control the fluid velocity by restricting the opening at the mouth of the tube.
Thus, sleeves are effective devices for repairing and modifying the heat flux and flow velocities in heat exchange tubes and properly shaped and properly disposed explosive charges facilitiate the installation of sleeves in tubes of heat exchangers.